A process for manufacturing a semiconductor device or a Flat Panel Display (FPD) such as a liquid crystal display device, includes a liquid processing of supplying a processing liquid, such as a chemical liquid or deionized water, to a surface of a semiconductor wafer (hereinafter, referred to as “wafer”) or a glass substrate, to remove particles or contaminants attached to the substrate.
According to one example of the liquid processing apparatuses to perform the liquid processing, a liquid processing apparatus is provided in which substrates are laid on a spin chuck one after another and the processing liquid is supplied to the surface of the substrate while rotating the substrate. In such a type of the liquid processing apparatus, a plurality of liquid processing modules that perform the liquid processing are connected to a common substrate carrying unit so that the substrate is continuously replaced while performing the liquid processing in the plurality of liquid processing modules (see Japanese Laid-Open Patent Publication No. 2008-34490, paragraph 0020, FIG. 1).
FIG. 14 illustrates an example of a liquid processing schedule of the liquid processing apparatus including twelve (12) liquid processing modules. In the liquid processing apparatus shown in FIG. 14, each liquid processing module is configured to perform a series of processes of loading a wafer→removing particles or organic contaminants with an alkaline chemical liquid (an alkaline chemical liquid processing)→removing the remaining alkaline chemical liquid with deionized water and spin-drying (a rinse cleaning)→removing a natural oxide film on the surface of the wafer with an acid chemical liquid (an acid chemical liquid processing)→removing the remaining acid chemical liquid with deionized water (a rinse cleaning)→supplying Isopropyl Alcohol (IPA) and spin-drying (an IPA drying)→unloading the wafer. In the meantime, for the simple description, FIG. 14 illustrates only one cycle of a series of the liquid processing.
In such a liquid processing apparatus, a module number (from module 1 to module 12) is assigned based on an arrangement order of the liquid processing modules and the wafer is loaded in the order of a smaller module number to perform the aforementioned processing in sequence. In this case, as shown in FIG. 14, with respect to the adjacently arranged module 1 and module 2, when the alkaline chemical liquid processing is performed in module 1, timing for concurrently performing the identical processing in module 2 is regularly generated.
Because of this, if various equipments related to the chemical liquid supply, drainage, exhaustion, or the like, are commonly provided for the plurality of modules of the liquid processing apparatus (hereinafter, such equipments are referred to as “a common usage system”), the common usage system is required to have a capacity for satisfying the maximum amount of consumption of the chemical liquid, the maximum drainage volume, or the maximum exhaustion volume for the plurality of modules. Such requirement causes the size of the common usage system to become large and to increase the expense of equipment. Further, the drained liquid and exhausted gas of the liquid processing apparatus are generally transferred to drainage processing equipment and exhaustion processing equipment of a whole factory. However, if the liquid processing apparatus is connected to the factory through the aforementioned common usage system, it is necessary to request the factory to design the maximum drainage volume and exhaustion volume in each common usage system as the maximum load and the decrease of such load requested on the factory has been a high-priority subject.